HelenOS 0.5.0 was released today. Some of the noteworthy new features of this major release are USB support, reimplemented networking stack with full TCP support and new network drivers (including Realtek RTL8139 and Intel E1000), read-only ext2 and ISO 9660 file system support, read-write MINIX FS support and several ported applications (GNU Binutils, PCC, MSIM). For a complete list of user-visible changes, see the release notes. The release files can be downloaded from the download page.

I remember seeing updates on this OS from time to time, but this is the first time I remember looking and being impressed by the graphics. Of course that isn't the only thing to be impressed by, but they seem to be aiming for becoming a "general purpose" OS rather soon, so that is perhaps a top priority.